Hi!
There is no other xenon housing made for our B7s. If you currently have the Halogen housing you should do the complete retrofit with a original bi-xenon housing. Buy it from ebay.de
If you are thinking about getting just xenonbulbs for your halogen housing i wouldn't recommend this, but if you have to the mtec kits are good quality kits that will fit right in your H7 mount.
Regards
Eirik